Mechanical speed-regulator.



No. 674,423. Patented May 2:, 19m. G. E. LOB.

MEGHANIGALSPEED REGULATOR. (Application filed 21, 1900.) (No Model.) 2 Sheets-Sheet l.

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No. 674,423. Patented May 21, I901.

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MECHANICAL SPEED REGULATOR.

(Application filed Aug. 21, 1900.)

2 Sheets-Sheet 2.

(No Model.)

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UNITED STATES.

' ATENT 0 FFIcE.

GUIDO E. LOB, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA, PENN- SYLVANIA.

MECHANICAL SPEED-REGULATOR.

SPECIFICATION formingpart of Letters Patent No. 674,423, dated May 21, 1901.

Application filed August 21, 1900. Serial N 0. 27,548. (No model.)

To all whom it may concern:

Be it known that I, GUIDO E. LOB, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Mechanical Speed-Regulators; and I do hereby-declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain improvements in mechanical speed-regulators particularly designed for dental engines, the object of my invention being to improve the speedregulator forming the subject of Letters Patent of the United States No. 628,947, granted July 18, 1899. The characteristic feature of the aforesaid patented speed-regulator is a friction-hemisphere and a frictionpulley carried by a pivoted arm and adapted to be pressed against and moved over the surface of said friction-hemisphere. These features are employed in my present invention; but instead of locating the friction hemisphere at a point some distance from the motor it is placed upon the motor-shaft. This, as well as other improvements, will be hereinafter fully described and claimed.

In the accompanying drawings, Figure 1 is a view in side elevation of the base or lower portion of an electric dental engine having my invention applied thereto, some portions being in vertical central section. Fig. 2 is a plan view of said engine with the motor removed and some parts shown in horizontal section.

The lower portion of the dental engine shown in the drawings consists of an electric motor A, mounted upon an upright post B, projecting from a base C, having legs C. Mounted directly upon the driving-shaft D of the motor A is a friction drive-wheel E, the outer surface of which is the section of a sphere. This friction drive-wheel E corresponds to and performs the same function as the friction-hemisphere B of the before-mentioned patent; but as it is in this instance actually somewhat less than a hemisphere, it will be herein designated the friction drive wheel. A friction-pulley F, adapted to bear against the outer curved surface of the friction drive-wheel, is carried at the outer end of an arm G, which, near its inner end, is pivoted at g g to a hub or box H, mounted to turn horizontally about the post B, which supports the motor. A foot-actuated lever or pedal I is pivoted to the box H at 'r' t, on the opposite side thereof, to which the frictionpulley-supporting arm G is pivoted, said arm and said lever or pedal being in alinement with each other. The inner end of the arm G is extended beyond its pivotsg g and forked, the forks G G being provided with segmental gears g g. The inner end of the lever I is also extended beyond its pivotst' t' and forked, the forks I I being provided with segmental gears i i, which mesh with the gears g g of the forks of the arm G. A screwrod J, projecting from a lug h on the box H,

passes through an opening 9 in an extension G of the arm G, and a coiled spring K, confined between said extension G and box H,

serves to normally force the friction-pulley.

F against the friction drive-wheel E with sufficient force to produce the requisite amount of friction. A nut J and jam-nut J are provided for regulating the tension of the spring K.

The engine to which my improvements are herein shown as applied is of the uprightstandard type, although my improvements could be applied to any other type of dental engine, such as the wall-bracket, suspension, &c. A vertical arm L rises from the top of the motor and is provided at its upper end with a socketed head L for the attachment of an upright engine-standard carrying the engine head and arm. These features form no part of my invention and as they may be of any desired pattern are not herein shown. The friction-pulley F is preferably provided with a rubber periphery F and a groove f. The driving belt or cord M, after passing about the groove fof the friction-pulley F, passes about suitable pulleys of the enginehead to impart motion to the hand-piece, also not shown.

It is not necessary to herein illustrate the electrical connections of the motor, although I have indicated at N, Fig. 2, the handle or knob ofa switch for turning on and off the current. This switch may be located on the engine-base, as shown, on the wall, or in any other convenient position. When the motor is supplied with current, by turning said switch the friction drive-wheel E rotates at a constant unvarying speed in a given direction. When the friction-pulley is opposite the center of the friction drive-wheel, which at this point e is slightly depressed or concaved, the friction-pulley, obviously, is inactive, although the friction drive-wheel may be rotating rapidly. In order to start the friction-pulley in one direction, it is moved to one side of the center of the friction drivewheel by moving the foot-pedal I sidewise in the proper direction. The position of the friction-pulley on the friction drive wheel determines the speed of said pulley. The greater the distance of the pulley from the center of the drivewheel the greater the speed of said pulley. By moving the pulley to the opposite side of the drive-wheel the direction of rotation of the pulley is reversed. The rotation of the friction-pulley may be instantly stopped no matter upon what point of the surface of the drive-wheel it may bear by simply depressing the foot-pedalLfor when said pedal is depressed the arm G, owing to the gear between the said pedal and arm, is rocked downward about its pivot g and the friction-pulley thrown out of contact with the friction drive-wheel. As soon as the footpedal is relieved of pressure the friction-pulley immediately resumes its contact with the rapidly-rotating drive-wheel at the same point it occupied before the contact was broken. In this way a quick stop of the engine may be secured without the necessity of moving the friction-pulleyto its inoperative central position and the same speed and direction of rotation be instantly restored.

Stop-lugs O O on the base serve to limit the horizontal movement of the foot-pedal I in opposite directions, and for the purpose of insuring the friction-pulley being returned exactly to its central inoperative position when it is desired to stop the engine the pedal I may be provided with a lug I adapted to engage a notch 0, formed in a flange or raised portion of the base C.

By placing the friction drive-wheel upon the motor-shaft and mounting the frictionpulley supporting and operating mechanism directly upon the motor-base a single compact apparatus, including a dental engine, motor,and mechanical speed-regulator,is provided, which as a whole can readily be moved from place to place.

While I regard the means for producing the quick stop of the friction-pulley in whatever position it may happen to be in as of considerable im portance,the regulator may be much simplified by its omission. In this case the arm G, box H, and foot-treadle I may be made integral or rigid, or the particular foot-treadle might be dispensed with and a rigid lever or foot-treadle made to project from the box H beneath the arm'G'r or directly from said arm.

A mechanical speedmegulator embodying the principles of my invention is especially applicable to engines employing an electric motor of. the alternating type, the direction of rotation ofwhich is not well adapted to be instantly reversed. It must be understood, however, that it is just as applicable to direct-current motors. In fact, its use is not confined to electric motors, as it is well suited for water and other motors.

I have herein indicated several obvious changes towhich my present improvements are susceptible, and I desire to have it further understood that the details of construction herein shown and described may be altered in various ways without departing from the principle of my invention.

I claim as my invention-- 1. The combination of a motor, a support therefor, a friction drive-wheel mounted directly upon the shaft of said motor, the driving-surface of said wheel being a section of a sphere, an arm pivoted directly to said motorsupport, a friction-pulley carried by said arm and adapted to be pressed against and moved over the surface of said friction drive-wheel, and means for moving said arm, substantially as and for the purpose described.

2. The combination'of a motor, a support therefor, a friction drive-wheel mounted directly upon the shaft of said motor, an arm pivoted directly to said motor-support, a f iiction-pulley carried by said arm and adapted to be pressed against and moved over the surface of said friction drive-wheel, and a lever or pedal for moving said arm, su bstantially as and for the purpose described.

3. The combination, in a mechanical speedregulator, of a motor, a friction drive-wheel mounted upon the shaft of said motor, the driving-surface of said Wheel being a section of a sphere, a box or hub having swiveling connection with said motor, an arm projecting from said box or hub, a friction-pulley carried by said arm and adapted to be pressed against and moved over the surface of said friction drive-wheel, and a lever or pedal pro jecting from said box or hub by means of which the arm may be moved, substantially as and-for the purpose described.

4. The combination, in a mechanical'sp'eedregulator, of a friction drive-wheel adapted to be rotated at a substantially uniform speed, a pivoted arm, a friction-pulley carried by said pivoted arm and adapted to be pressed against and moved over the surface of said friction drive-wheel, whereby the speed of said friction-pulley may be varied and the direction of rotation reversed, means for so moving said arm, and means for throwing said friction-pulley out of contact with the friction drive-wheel for the purpose of instantly stopping the rotation of said friction-pulley at any point itmay bear upon the friction driveacross the face of the friction drive-wheel by lateral movement of said lever or pedal, and I 5 said friction-pulley be thrown out of frictional engagement with said friction drive-Wheel by depressing said lever or pedal, substantially as and for the purpose described.

In testimony whereof I aflix my signature 20 in presence of two witnesses.

GUIDO E. LOB.

Witnesses:

BERNARD 0. HOYNG, FRANK G. SUTTON. 

